Harvard Psychological Studies, Volume 1 eBook

An analysis of the constituent intervals of the unit
group, as shown in the second and third lines of the
table, reveals the existence of a complex subordinate
rhythm. The two components of the rhythmical group
do not increase and decrease concomitantly in temporal
value in composing the alternate long and short measures
of the fluent rhythm. The movement involves a
double compensating rhythmical change, in which the
two elements are simultaneously in opposite phases
to each other. A measure which presents a major
first interval contains always a minor second; one
introduced by a minor first concludes with a major
second. The ratios of these two series of periodic
variations must themselves manifestly be different.
Their values are, for the first interval of the measure,
1.000:1.214; and for the second interval, 1.000:0.764.
The greater rhythmical differentiation marks the second
of the two intervals; on the variations of this second
interval, therefore, depends the appearance of that
larger rhythm which characterizes the series.
The ratios of these primary intervals are less consistently
maintained than are those of the rhythmical measures
built out of them. It will be noted that in both
intervals there is a tendency for the value of the
difference between those of alternate groups to increase
as the tapping progresses. This change I have
interpreted as indicative of a progressive definition
in the process of rhythmization, depending on an increase
in cooerdination and differentiation of the reactions
as the series advances.

A simple stress on alternate elements was next introduced
in the series, forming a simple trochaic measure repeated
without interruption. The quantitative results
follow, arranged as in the preceding experiment.

Here again there is no progressive acceleration or
retardation. The rhythmical differentiation of
alternate measures is very slight—­the average
ratio of the first to the second being 1.000:0.993—­but
is of the same type as in the preceding. The
excess in the amount of this differentiation presented
by the first type of reaction over the second may
be due to the presence of a tendency to impart rhythmical
character to such a series of reactions, which, prohibited
in one form—­the intensive accent—­finds
expression through the substitution for this of a
temporal form of differentiation.

In this trochaic rhythm the phases of variation in
the constituent intervals of the measure are concomitant,
and their indices of differentiation almost identical
with each other. Their values are, for the first,
1.000:0.979; and for the second, 1.000:0.995.
The higher index is that of the first interval, that,
namely, which follows the accented beat of the measure,
and indicates that the rhythmical change is due chiefly
to a differentiation in the element which receives
the stress.